Tail-block of sawmills



UNITED i STATES PATENT OFFICE.

CHARLES D. WRIGHT, OF EAST HADDAM, CONNECTICUT.

TAIL-BLOCK OF SAWMILLS.

T o all wiz-0m t may concern:

Be it known that I, CHARLES D. WRIGHT, of East Haddam, in the county of Middlesex and State of Connecticut, have invented a new and useful Improvement in the Tail- Blocks of Sawmills; and I do hereby de- Clare that the following is a full and eXact description of the construction and operation of said improvement, reference being had to the annexed drawings, making part of this specification, of which- Figure l, is a rear perspective view, and Fig. 2, a sectional representation of the ratchet wheel, dog and lever in the position described for reversing the motion of the slide.

The general form and position of this block are similar to those in common use; and the improvement consists of certain mechanical appendages, whereby the log or timber resting upon this tail-block, and in the process of being sawed, is by the running back of the carriage at the termination of each run of the saw, removed laterally any required distance, either to the right or left, and amply secured in its new position, without the aid of the sawyer or attendant.

The block A, is of ordinary size, and secured upon the ends of the carriage beams B, C, in the ordinary manner. In front of the block is a large rabbet occupying a space equal to one third of the block, and within this rabbet is a slide D, in the upper part of which is another rabbet to receive the end of the log to be sawed; the end of the log resting upon the projecting section of the lower part of the slide. The log is secured to this slide by dogs attached to the eyes or staples e, e, e, e. A horizontal rack F, is attached to the slide, and the teeth of the rack take to those of any ordinary pinion below (not represented) which 4is mounted on the axle shaft of the ratchet G, so that by the rotary motion of the ratchet, the slide is moved to the right or left. A wedgeshaped chock, or inclined plane H, is attached to the ioor near the rail which supports the carriage beam B, and is temporarily secured by bolts or otherwise, but may be removed forward or back as occasion requires, to correspond with the length of the log being sawed. A horizontal lever I, called the elevator, is connected to the block A, by a pivot joint at J, and extends thence nearly parallel to the block, to a vertical groove K, in the side of the beam B, and

Specification of Letters Patent No. 5,537, dated April 25, 1848.

terminates within the groove in which it moves up and down freely, being supported by a. small friction pulley L near the end; so that when the carriage passes back the pulley rolls up the inclined plane, whereby the elevator becomes elevated though ordinarily pressed down by the spring M. A knee-lever N, O, is connected to the block by a pivot through the angle, and in such a posit-ion that one branch or prong O, rests on the elevator, while the other prong N rises nearly perpendicular, and near the upper end has a pin projecting horizontally and parallel to its aXle pivot. A short vertical pawl lever P, Q, is mounted centrally on the ratchet aXle, the lever passing between the ratchet and the block; and to the head of this lever is attached a forked pawl P, which takes to the teeth of the ratchet G. This pawl has two points for the purpose of being made to operate the wheel in either direction. Two pins project horizontally from the pawl lever, one immediately under the pawl and the other at Q, and aconnecting rod R, having a hole or notch at each end, is made to connect the two levers by the pins near N, and P, so

that when the elevator passes up in the inclined plane H, the connecting rod and pawl are moved to the right, moving the ratchet, pinion and slide to the right.. To the right of the ratchet a balance lever S, T, is attached to the block by a horizontal central pivot, and the right end T, of this lever is connected to the elevator at U, by a vertical connecting rod T, U. The connection of this rod to the elevator is effected by means of a. horizontal pin projecting from the elevator and passing through a vertical slot in the rod. The left end of the balance lever is connected to, or passes under the rear end of a horizontal bar S, W, placed longitudinally or parallel with the carriage, and which passes through the block, and the forward end rests upon the top of the rack at W. This bar or gage (as it is called,) is secured in its place by a vertical thumbscrew V, which passes down through the center thereof. The weight of the elevator is sustained ordinarily by the rod T, U, and consequently a corresponding pressure upward is sustained by the S, end of the gagelever while with a corresponding force, the forward end of this gage-lever presses upon the ratchet; thus the ordinary position of the elevator, and. consequently the limits of its vertical motion, (and the lateral motion of the slide and log) are governed by the vertical screw V. The lateral motion of the slide and log is more accurately gaged Or limited, however, by means of the gage stop a, c, On the face of the block, and Which is held fast in any required position by a thumb-screw at c, and stops the motion of the connecting rod R. And when the elevator is raised by passing up the inclined plane, the rack is relieved from the pressure of the gage-lever, and the slide is moved as above described. When the slide and log are to be moved to the left, the connecting rod R, is applied to connect the pins N and Q, and the paWl P, is reversed so as to impinge upon the ratchet in the opposite direction, as shown in Fig. 2.' The hand lever X, Y, with the dog Z, connected, are not permanently attached to the tail-block, but are used occasionally to turn the ratchet, the end of the dog being made to apply to the teeth thereof.

The rack F, Which is made of iron or brass, may be made large enough to constithe top thereof. This rack may be placed near the lbottom of the slide, and With the teeth thereof point-ing upward, so as to take to the under side of the pinion instead of the upper side as above described. The

block may also be surmounted With a. plate of iron.

Vhat I claim as my invention and desire to secure by Letters Patent, is

The arrangement Of the elevator I, the knee-lever N, O, the pawl-lever P, Q, the pawl P, the-connecting rod R, the balancelever S, T, the vertical connecting rod T, U, the gage-lever S, W', the iron back b, b, and the regulating screw V, in combination with the tail-block, slide, rack, and ratchet as herein described.

CHARLES D. WRIGHT. .Vitnesses F. W. JOHNSON, RUFUs PORTER. 

